There is a known way of incorporating light-emitting diode modules (LED modules) in the edges of single-layer or laminated glazing units, in such a way that the light emitted by the LEDs enters through the edge of a glass sheet and is guided by the sheet to a diffusing element, also known as a light extraction means.
These illuminating glazing units essentially have the function of ambient lighting or light signaling, using low-power LEDs for this purpose. The light output of these edge-illuminated glazing units is generally limited because of the losses of light due to light absorption by the glass acting as the waveguide and/or by the materials in the proximity thereof.
However, attempts to overcome this problem by using more powerful LEDs give rise to a problem of overheating. This is because it is often difficult to remove the heat generated by LED modules during their operation in a confined environment. In the field of motor vehicles or other fields, it is often necessary to protect the LED modules from the action of moisture which is always present. This protection is commonly provided either by encapsulation, that is to say by overmolding the LED modules with an organic polymer injected in liquid form and then hardened, or by housing the LED modules in a removable or non-removable way in more or less watertight casings. Prolonged overheating of LEDs almost inevitably leads to undesired shortening of their life.